Tongue-and-groove flooring is typically installed with a pneumatic nailer or stapler which drives a fastener at an angle, as 45 degrees, through the edge of a flooring strip from a point above the tongue and into the subfloor. The pneumatic tool is positioned to drive the fastener with an adapter which rests on the subfloor and locates the nose of the tool at the desired height and angle. However, tongue and groove flooring is available in various thicknesses and with various tongue configurations. Each different style of flooring requires a different adapter.